Returns a relative comparison of two strings. The result is 0 if both strings are different in every character and 1 if they are absolutely equal. In every other case a value between those is arisen which is the higher the more fragments of one string can be found in the other one. The exact formel is:

StrComp(S1,S2) = 2*n/(Length(S1)+Length(S2))
whereas n is the number of equal charakters (directed from left to right).